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Application of Raman spectroscopy in carbon nanotube-based polymer composites

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Chinese Science Bulletin 2010年第35期55卷 3978-3988页

作者： GAO Yun LI LingYun tan pingheng LIU LuQi ZHANG Zhong National Center for Nanoscience and Technology of China Beijing 100190 China State Key Laboratory for Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Academy for Advanced Interdisciplinary Studies Peking University Beijing 100871 China Graduate School of Chinese Academy of Sciences Beijing 100190 China

Raman spectroscopy has been widely used to identify the physical properties of carbon nanotubes(CNTs),and to assess their functionalization as well as ***,Raman spectroscopy has become a powerful tool to characterize the interfacial properties between CNTs and polymer *** review provides an overview of micro-Raman spectroscopy of CNTs and its application in studying CNT reinforced polymer *** on the specific Raman band shifts relating to the mechanical deformation of CNTs,Raman scattering can be used to evaluate the interactions between the CNTs and the surrounding polymer in the composites,and to detect the phase transitions of the polymer,and investigate the local stress state as well as the Young's modulus of the ***,we also review the current progress of Raman spectroscopy in various CNT macroarchitectures(such as films,fibers as well as composite fibers).The microscale structural deformation of CNT macroarchitectures and strain transfer factors from macroscale architectures to microscale structures are *** on an in situ Raman-tensile test,we further predict the Young's modulus of the CNT macroarchitectures and reveal the dominating factors affecting the mechanical performances of the CNT macroarchitectures.

关键词：聚合物复合材料拉曼光谱技术碳纳米管应用杨氏模量复合纤维物理性质 CNTs

Interlayer interactions in anisotropic atomically thin rhenium diselenide

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Nano Research 2015年第11期8卷 3651-3661页

作者： Huan Zhao Jiangbin Wu Hongxia Zhong Qiushi Guo Xiaomu Wang Fengnian Xia Li Yang pingheng tan Han Wang Ming Hsieh Department of Electrical Engineering University of Southern California Los Angeles CA 90089 USA State Key Laboratory of Supeflattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China Department of Physics Washington University in St Louis St Louis MO 63130 USA Department of Electrical Engineering Yale University New Haven CT06511 USA State Key Laboratory for Mesoscopic Physics and Department of Physics Peking University Beijing 100871 China

In this work, we study the interlayer phonon vibration modes, the layer-number- dependent optical bandgap, and the anisotropic photoluminescence （PL） spectra of atomically thin rhenium diselenide （ReSe2） for the first time. The ultralow frequency interlayer Raman spectra and the polarization-resolved high frequency Raman spectra in ReSe2 allow the identification of its layer number and crystal orientation. Furthermore, PL measurements show the anisotropic optical emission intensity of the material with its bandgap increasing from 1.26 eV in the bulk to 1.32 eV in the monolayer. The study of the layer-number dependence of the Raman modes and the PL spectra reveals relatively weak van der Waal＇s interaction and two-dimensional （2D） quantum confinement in the atomically thin ReSe2. The experimental observation of the intriguing anisotropic interlayer interaction and tunable optical transition in monolayer and multilayer ReSe2 establishes the foundation for further exploration of this material in the development of anisotropic optoelectronic devices functioning in the near-infrared spectrum, which is important for many applications in optical communication and infrared sensing,

关键词： rhenium diselenide Raman photoluminescence anisotropy

Highly sensitive phototransistors based on twodimensional GaTe nanosheets with direct bandgap

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Nano Research 2014年第5期7卷 694-703页

作者： Pingan Hu Jia Zhang Mina Yoon Xiao-Fen Qiao Xin Zhang Wei Feng pingheng tan Wei Zheng Jingjing Liu Xiaona Wang Juan C. Idrobo David B. Geohegan Kai Xiao Key Lab of Microsystem and Microstructure Harbin Institute of Technology Ministry of Education No. 2 Yikuang Street Harbin 150080 China Center for Nanophase Materials Sciences Oak Ridge National Laboratory One Bethel Valley Road Oak Ridge TN 37831 USA State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Highly sensitive phototransistors based on two-dimensional （2D） GaTe nanosheet have been demonstrated. The performance （photoresponsivity, detectivity） of the GaTe nanosheet phototransistor can be efficiently adjusted by using the applied gate voltage. The devices exhibit an ultrahigh photoresponsivity of 274.3 AW^-1. The detectivity of 2D GaTe devices is -10^12 Jones, which surpasses that of currently-exploited InGaAs photodetectors （10^11-10^12 Jones）. To reveal the origin of the enhanced photocurrent in GaTe nanosheets, theoretical modeling of the electronic structures was performed to show that GaTe nanosheets also have a direct bandgap structure, which contributes to the promotion of photon absorption and generation of excitons. This work shows that GaTe nanosheets are promising materials for high performance photodetectors.

关键词： photodetector gallium telluride two-dimensional semiconductor nanosheet

新风胶囊通过抑制miR-155/SOCS1/NF-κB通路降低干燥综合征患者血液高凝状态

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细胞与分子免疫学杂志 2016年第10期32卷 1366-1371页

作者：朱福兵刘健王桂珍方利章平衡谈冰安徽中医药大学安徽合肥230038 安徽中医药大学第一附属医院风湿免疫科安徽合肥230031

目的探讨新风胶囊(XFC)改善干燥综合征(SS)患者高凝状态与miR-155/细胞因子信号传送阻抑物(SOCS1)/核因子κB(NF-κB)信号转导通路的关系。方法将66例SS患者随机分为XFC治疗组和硫酸羟氯喹(HCQ)治疗对照组各33例,分别予XFC及HCQ治疗。另... 详细信息

目的探讨新风胶囊(XFC)改善干燥综合征(SS)患者高凝状态与miR-155/细胞因子信号传送阻抑物(SOCS1)/核因子κB(NF-κB)信号转导通路的关系。方法将66例SS患者随机分为XFC治疗组和硫酸羟氯喹(HCQ)治疗对照组各33例,分别予XFC及HCQ治疗。另选20名健康者作为正常对照组。全自动凝血仪测定凝血酶原时间(PT)、活化部分凝血酶原时间(APTT)、纤维蛋白原(FIG)、凝血酶时间(TT)、D-二聚体(D-D);ELISA检测外周血血清白细胞介素1β(IL-1β)、IL-4、IL-10、肿瘤坏死因子α(TNF-α)、P50、P65、NF-κB抑制蛋白α(IκBα)水平;同时采用实时荧光定量PCR检测p65、p50、IκBαmRNA水平;一步法荧光定量PCR反应测定miR-155含量;Western blot法检测P65、P50、SOCS1蛋白水平;魏氏法测定血沉(ESR);全自动生化分析仪测定超敏C反应蛋白(hs-CRP)。结果与NC组比较,SS患者凝血参数D-D、FIB明显升高;SS患者外周血miR-155、IL-1β、TNF-α、P50、P65、IκBα及炎症指标hs-CRP、ESR水平明显升高;IL-4、IL-10水平明显降低;凝血参数与细胞因子、NF-κB信号转导通路及炎症指标明显相关。药物干预后,两组凝血参数和相关实验室指标均有部分改善;与对照组比较,XFC组有效率显著高于HCQ组,且在降低FIB、D-D、miR-155、TNF-α、IL-1β、P50、P65、ESR、hs-CRP水平,增加SOCS1,IL-4、IL-10水平方面明显优于HCQ组。结论 XFC能有效降低SS患者血液高凝状态,其机制与抑制miR-155/SOCS1/NF-κB信号通路有关。

关键词：干燥综合征血液高凝状态新风胶囊 NF-κB信号通路 miR-155

内嵌自组装InAs量子点调制掺杂场效应管的光电特性

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Journal of Semiconductors 2005年第Z1期26卷 238-242页

作者：曾宇昕刘伟杨富华徐萍章昊边历峰谭平恒郑厚植曾一平中国科学院半导体研究所超晶格国家重点实验室北京100083

研究了阱中生长自组装InAs量子点的光谱特性,获得了室温1.265μm近红外荧光发光,探讨了与量子点尺寸分布相关的发光峰随温度的超常红移现象.制备了内嵌InAs量子点的异质结调制掺杂场效应晶体管,获得了高耐压的场效应器件电学特性,并有... 详细信息

研究了阱中生长自组装InAs量子点的光谱特性,获得了室温1.265μm近红外荧光发光,探讨了与量子点尺寸分布相关的发光峰随温度的超常红移现象.制备了内嵌InAs量子点的异质结调制掺杂场效应晶体管,获得了高耐压的场效应器件电学特性,并有望制成新型红外光电探测场效应管.

关键词： InAs量子点光致发光谱调制掺杂场效应晶体管

量子棒及其异质结的超低频拉曼光谱及有限元分析

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光散射学报 2018年第3期30卷 230-235页

作者：林妙玲 MISCUGLIO Mario STASIO Francesco Di KRAHNE Roman 谭平恒中国科学院半导体研究所半导体超晶格国家重点实验室北京100083 中国科学院大学材料科学与光电技术学院北京100049 意大利技术研究院纳米化学系热那亚16163 意大利热那亚大学化学与工程学院热那亚16146

硫族化镉纳米微晶由于具有发光效率高和发射波长可调谐等优良性质在光电器件中有重要的应用,CdSe/CdS点-棒异质结量子点是典型代表之一。本文中通过非共振拉曼方法探测了该量子点在5~50cm-1的声学声子模,利用不同模式的偏振特性,清晰地... 详细信息

硫族化镉纳米微晶由于具有发光效率高和发射波长可调谐等优良性质在光电器件中有重要的应用,CdSe/CdS点-棒异质结量子点是典型代表之一。本文中通过非共振拉曼方法探测了该量子点在5~50cm-1的声学声子模,利用不同模式的偏振特性,清晰地指认了球状核壳异质结量子点的扭转模式和径向呼吸模、棒状和点-棒异质结量子点的伸缩模和径向呼吸模等,并观察到了棒状量子点和点-棒异质结量子点的电子拉曼散射。同时发现点-棒异质结量子点的径向呼吸模较尺寸相当的纳米棒量子点发生红移。利用有限元方法形象模拟各量子点声学模的振动形式,并发现点-棒异质结量子点呼吸模振动的局域性。随后,引入局域有效声速的概念,利用改进的Lamb定律,成功解释了该红移是由CdSe核区域声速的减小所导致的,并再次验证该呼吸模局域在核附近区域。该研究对于表征和研究量子点中的限制性声学模具有重要意义,声学模和光学跃迁均局域在量子点附近区域的特性,对调控其激子-声子耦合和相关的光学性质具有重要指导意义。

关键词： CdSe/CdS点-棒异质结量子点径向呼吸模局域性有限元 Lamb定律

Movement of lateral hyporheic flow between stream and groundwater

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Science China Earth Sciences 2017年第11期60卷 2033-2040页

作者： ZHANG Yu WANG JianLi YANG pingheng XIE ShiYou School of Geographical Sciences Southwest UniversityChongqing Key Laboratory of Karst EnvironmentKey Laboratory of Eco-environments in Three Gorges ReservoirMinistry of EducationChongqing 400715China Field Scientific Observation&Research Base ofKarst Eco-environments at Nanchuan in Chongqing Ministry of Land and ResourcesChongqing 408435China Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The hyporbeic zone plays an important role in groundwater and stream water quality protection. To investigate the stream-groundwater interaction mechanisms in the lateral hyporheic zone, this study examined Ma＇an Creek in Chongqing during the dry season from December 2015 to April 2016. The water level, water temperature, pH and CF concentration in the hyporheic zone and groundwater were monitored in situ. The sediment permeability coefficient, stable isotopes of hydrogen and oxygen and concentration of DOC were analyzed. The results show that the water level changes of hyporheic zone and the movement of hyporheic flow were influenced significantly by the permeability coefficient of sediment. The hyporheic flow approximately 10 cm from the stream bank was clearly affected by precipitation infiltration and evapotranspiration. During the study period, the groundwater recharged the stream, and the impact of groundwater on the hyporheic flow gradually decreased with the flow path. The hyporheic flow approximately 30 cm from the stream bank was still mainly affected by groundwater. Approximately 10-30 cm from the stream bank, the mixing of groundwater with precipitation and stream water intensified. Due to the sediment properties, moisture accumulated approximately 10 cm from the stream bank and drained into the stream via hyporheic flow, with potential impacts on stream water quality.

关键词： Hyporheic zone Lateral hyporheic flow Permeability coefficient Hydrogen and oxygen isotopes Ma'an Creek

Retrieval of leaf biochemical properties by inversed PROSPECT model and hyperspectral indices:an application to Populus euphratica polymorphic leaves

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Journal of Arid Land 2012年第1期4卷 52-62页

作者： ZhongGuo MA Xi CHEN Quan WANG pingheng LI Guli Jiapaer Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Faculty of Agriculture Shizuoka University Shizuoka 422-8529 Japan

Leaf biochemical properties have been widely assessed using hyperspectral reflectance information by inversion of PROSPECT model or by using hyperspectral indices, but few studies have focused on arid ecosystems. As a dominant species of riparian ecosystems in arid lands, Populus euphratica Oliv. is an unusual tree species with polymorphic leaves along the vertical profile of canopy corresponding to different growth stages. In this study, we evaluated both the inversed PROSPECT model and hyperspectral indices for estimating biochemical properties of P. euphratica leaves. Both the shapes and biochemical properties of P. euphratica leaves were found to change with the heights from ground surface. The results indicated that the model inversion calibrated for each leaf shape performed much better than the model calibrated for all leaf shapes, and also better than hyperspectral indices. Similar results were obtained for estimations of equivalent water thickness （EWT） and leaf mass per area （LMA）. Hyperspectral indices identified in this study for estimating these leaf properties had root mean square error （RMSE） and R2 values between those obtained with the two calibration strategies using the inversed PROSPECT model. Hence, the inversed PROSPECT model can be applied to estimate leaf biochemical properties in arid ecosystems, but the calibration to the model requires special attention.

关键词： Populus euphratica inversed model hyperspectral index vertical profile polymorphic leaf

The phytolith carbon sequestration in terrestrial ecosystems:the underestimated potential of bamboo forest

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Ecological Processes 2023年第1期12卷 872-883页

作者： Xuekun Cheng Huiru Lv Shuhan Liu Chong Li pingheng Li Yufeng Zhou Yongjun Shi Guomo Zhou State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityLin’anHangzhou 311300China Zhejiang Province Key Think tank:Institute of Ecological Civilization Zhejiang A&F UniversityLin’anHangzhou 311300China Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration of Zhejiang Province Zhejiang A&F UniversityLin’anHangzhou 311300China School of Environmental and Resources Science Zhejiang A&F UniversityLin’anHangzhou 311300China

Background Terrestrial ecosystems contain significant carbon storage,vital to the global carbon cycle and climate *** in human production activities and environmental factors affect the stability of carbon storage in *** sequestration in plant phytoliths offers a sustainable method for long-term carbon *** occluded in phytoliths(PhytOC)is a kind of carbon that can be stable and not decomposed for a long time,so it is crucial to conduct more in-depth research on *** We undertook a meta-analysis on PhytOC across global terrestrial ecosystems,analyzing 60 articles,encapsulating 534 *** observed notable differences in phytolith and PhytOC contents across various *** forest ecosystems exhibited the highest vegetation phytolith and PhytOC content,while soil phytolith content was most prominent in bamboo forests and PhytOC content in *** activities,such as grassland grazing,had a lesser impact on soil PhytOC transport than actions like cutting and tillage in croplands and *** study separated bamboo ecosystems,analyzing their PhytOC content and revealing an underestimation of their carbon sink *** Notwithstanding our findings,phytoliths’intricate environmental interactions warrant further exploration,crucial for refining ecosystem management and accurately estimating PhytOC *** deepened understanding lays the foundation for studying phytoliths and the carbon sink dynamics.

关键词： Carbon sequestration Phytoliths PhytOC Terrestrial ecosystem Soil carbon

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